The invention discloses a method for preparing a bimetallic nanometer alloy composite material by taking graphene as a carrier. The method comprises the following steps of: by taking a precious metal N salt (N=Pd, Pt) and a transition metal M salt (M=Co, Ni and Cu) as precursors and taking graphene oxide as a matrix, reducing the components by employing a reducing agent; and finally, washing, filtering, drying, grinding and roasting to obtain the high-purity graphene bimetallic nanometer composite material. The composite material has high nanoparticle load capacity, stable structure, high uniformity and high dispersing property, has high binding force with the graphene and is high-efficiency in preparation method, low in cost, simple in process and suitable for industrial production. The composite material can be widely applied to the fields of magnetic targeting materials, various catalysts, electromagnetic shielding wave-absorbing materials, super-capacitor electrode materials and other related function materials.